package tgipl3.easy.bestBowler.minified;

import java.io.IOException;

public class UserMainCode
{
	static int output1,d,i;
	static void GetBestBowlerCount(int p,String q){
		double s=0;
		while(++i<q.length()&&(q.charAt(i)%16>9&&(output1+=s/(d*53))>=(s=d=0)||(s+=q.charAt(i))>++d));
	}
	public static void main(String[] args) throws IOException {
		String[] inputs = "5:{2210011,1115422363,4645637468,023013,1323402022}".split(":");
		GetBestBowlerCount(Integer.parseInt(inputs[0]), inputs[1]);
		System.out.println(output1);
	}
}